Android is the world's leading mobile operating system. It also has one of the most active developer communities. Since Google has made Android open-source, it means the source code of the operating system (OS) itself is available to developers, and anyone can make their own version of Android if they know what they are doing.
This is the reason why the Android OS varies from Google's Pixel devices to Samsung's OneUI and Xiaomi's MIUI and everything else. This also means that individual developers can create their own custom versions of Android, also known as custom ROMs. Developers can create these custom ROMs and add new features and functionality that aren't available in stock/vanilla Android.
A custom ROM is essentially a firmware based on the Android source code provided by Google. A lot of people prefer custom ROMs because of the functionality they offer, and the ability to customise many things on the phone.
Another big reason why many Android enthusiasts flock to custom ROMs is that their devices stop getting new software updates after a couple of years and having a custom ROM offers them the ability to improve functionality and get their hands on the new software.
Here's a quick guide on how you can install a stable custom ROM on your device.
How to Install a Custom ROM
Create a Backup
The first thing to do before installing a new ROM on your device is to back up all your data.
A backup is essential before you do any big changes on your device, and even more so while flashing a custom ROM. The best kind is a NANdroid backup, which is basically an image of your current device settings. This can be used if something goes wrong during the flashing process.
1. Reboot your phone and enter recovery mode. On most devices, this can be done by holding down the Power key and Volume Down key for 5 seconds.
2. Head to "Backup" or "Nandroid" in the recovery mode. You may see an option to give the backup a name, which you can do for your convenience. Confirm the settings and let it finish.
Create Recovery and Unlock Bootloader
You will be required to create a recovery file. You can choose between TWRP or ClockworkMod custom recoveries. TWRP is the most popular choice and you can read this article to find out how you can set it up on your device.
You also have to unlock your device's bootloader. You can look at popular forums like xda-developers for instructions on how to do it for your device.
(Warning: Doing this usually will void your device’s warranty. Unlocking the bootloader also wipes all data on the device so it’s better if you create a backup on your PC beforehand)
Download and Flash the ROM
The next step is choosing the right custom ROM. You may want to explore the internet and some developer forums to find the best custom ROM for you, and also one that is available for your phone. Once you've found it, download the .zip file either directly onto your phone or onto your PC and later transfer it via USB.
- Once the download is complete, reboot the phone into recovery mode
- Head to "Install" section of the recovery
- Select the .zip file for the ROM that you have already downloaded
- Wait till the installation is finished
Download Google Apps
You will also be required to download Google Apps (GApps) for your new ROM. This is required because unlike Android, Google apps are not open source. Find the right GApps corresponding to your ROM and your phone.
GApps can be flashed and installed in the same way as flashing the ROM.